Development of a Test Method to Evaluate both Stiffness and Interaction of Compatibility Performance 2008-01-0816

Compatibility is important in order to secure mutual protection in collisions between large and small vehicles. To enhance compatibility, good structural interaction and stiffness matching are important elements. This paper proposes a test method that uses a moving deformable barrier (MDB) to evaluate compatibility performance that includes not only structural interaction but also stiffness matching.

This new deformable barrier is aimed at the simulation of offset Vehicle-to-Vehicle collisions with compact vehicles. This simulation is based on real world crash research, and takes into account three separate load interactions between the impacting vehicles. These areas of interaction include the impacting vehicle's power unit to the opposing vehicle's wheel, the impacting vehicle's lower rail to the opposing vehicle's lower rail, and the impacting vehicle's wheel to the opposing vehicle's power unit. In general, the largest disparity in stiffness can be found between the power unit and the wheel, with the power unit being stiffer than the wheel. These factors were studied with both impacting vehicles being modeled as a combination of three springs. As a result, a more accurate estimate of vehicle loading in a vehicle-to-vehicle collision is obtained by using three individual load paths across the width of the vehicle as opposed to the uniform stiffness simulated in a conventional barrier.

In order to simulate the front body stiffness of a typical compact vehicle, a newly developed deformable barrier is proposed. The barrier has several divided honeycomb layers of varying stiffness both horizontally and longitudinally. The results using the new MDB were closer to those obtained in the Vehicle-to-Vehicle testing, as compared to-those of the conventional barrier test.

Finally, the proposed MDB shows promise for the evaluation of compatibility performance by more accurately simulating Vehicle-to-Vehicle collisions with compact vehicles.